Photo by Joe Raedle/Getty Images(FERGUSON, Mo.) — The police officer accused of fatally shooting Michael Brown, 18, in Ferguson, Mo. earlier this month has been interviewed by local investigators and will be given the chance to testify before a grand jury.

A spokesman for St. Louis County Prosecutor Robert McCulloch, Edward Magee, said on Tuesday that the St. Louis County Prosecutor will try to begin presenting evidence to the grand jury on Wednesday. That decision remains dependant on witness availability.

In addition to the local investigation, a federal investigation remains ongoing into the fatal shooting of Michael Brown that has prompted days of protests, as well as clashes between police and protesters.

U.S. Attorney General Eric Holder is expected to visit Ferguson on Wednesday, with Sens. Claire McCaskill, D-Mo., and Roy Blunt, R-Mo. joining him. Holder wrote an op-ed published in Tuesday’s St. Louis Post Dispatch ahead of his arrival, saying that “hundreds” have already been investigated as part of the FBI and Department of Justice investigation.

Holder also called for an end to the violence that has marred protests repeatedly over the last week. “Although these acts have been committed by a very small minority — and, in many cases, by individuals from outside Ferguson, they seriously undermine, rather than advance, the cause of justice,” Holder wrote. He also added that violence interrupts the, “deeper conversation that the legitimate demonstrators are trying to advance.”

As of Tuesday night, the Missouri National Guard will remain in Ferguson, once again operating under the command of the Missouri Highway Patrol to provide protection for the Unified Command Center.

Also announced on Tuesday was the funeral for Michael Brown, which will take place on Monday, August 25.

Gov. Jay Nixon released a statement on the ongoing tension on Tuesday, calling the shooting a “tragedy,” while echoing Holder’s calls for peace. Officers, Nixon said, have tried to, “protect the public, while at the same time preserving citizens’ rights to express their anger peacefully.” Once peace is achieved, “a vigorous prosecution must now be pursued,” against the officer, Nixon said.

Perhaps more important, Nixon said, once peace and justice are achieved, “we must remain committed to rebuilding the trust that has been lost, mending what has been broken, and healing the wounds we have endured.”

In his statement, Nixon also declined to ask McCulloch to recuse himself from the investigation despite some residents claiming the prosecutor has biases in favor of police.